package com.dream.testtubebaby.utils;

import android.graphics.BitmapFactory;
import android.util.DisplayMetrics;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;

import java.io.InputStream;
import java.lang.reflect.Field;

/**
 * Created by zhy on 15/8/11.
 */
public class ImageUtils {
	/**
	 * 根据InputStream获取图片实际的宽度和高度
	 *
	 * @param imageStream
	 * @return
	 */
	public static ImageSize getImageSize(InputStream imageStream) {
		BitmapFactory.Options options = new BitmapFactory.Options();
		options.inJustDecodeBounds = true;
		BitmapFactory.decodeStream(imageStream, null, options);
		return new ImageSize(options.outWidth, options.outHeight);
	}

	public static class ImageSize {
		int width;
		int height;

		public ImageSize() {
		}

		public ImageSize(int width, int height) {
			this.width = width;
			this.height = height;
		}

		@Override
		public String toString() {
			return "ImageSize{" + "width=" + width + ", height=" + height + '}';
		}
	}

	public static int calculateInSampleSize(ImageSize srcSize,
			ImageSize targetSize) {
		// 源图片的宽度
		int width = srcSize.width;
		int height = srcSize.height;
		int inSampleSize = 1;

		int reqWidth = targetSize.width;
		int reqHeight = targetSize.height;

		if (width > reqWidth && height > reqHeight) {
			// 计算出实际宽度和目标宽度的比率
			int widthRatio = Math.round((float) width / (float) reqWidth);
			int heightRatio = Math.round((float) height / (float) reqHeight);
			inSampleSize = Math.max(widthRatio, heightRatio);
		}
		return inSampleSize;
	}

	/**
	 * 计算合适的inSampleSize
	 */
	public static int computeImageSampleSize(ImageSize srcSize,
			ImageSize targetSize, ImageView imageView) {
		final int srcWidth = srcSize.width;
		final int srcHeight = srcSize.height;
		final int targetWidth = targetSize.width;
		final int targetHeight = targetSize.height;

		int scale = 1;

		if (imageView == null) {
			scale = Math.max(srcWidth / targetWidth, srcHeight / targetHeight); // max
		} else {
			switch (imageView.getScaleType()) {
			case FIT_CENTER:
			case FIT_XY:
			case FIT_START:
			case FIT_END:
			case CENTER_INSIDE:
				scale = Math.max(srcWidth / targetWidth, srcHeight
						/ targetHeight); // max
				break;
			case CENTER:
			case CENTER_CROP:
			case MATRIX:
				scale = Math.max(srcWidth / targetWidth, srcHeight
						/ targetHeight); // min
				break;
			default:
				scale = Math.max(srcWidth / targetWidth, srcHeight
						/ targetHeight); // max
				break;
			}
		}

		if (scale < 1) {
			scale = 1;
		}

		return scale;
	}

	/**
	 * 根据ImageView获适当的压缩的宽和高
	 *
	 * @param view
	 * @return
	 */
	public static ImageSize getImageViewSize(View view) {

		ImageSize imageSize = new ImageSize();

		imageSize.width = getExpectWidth(view);
		imageSize.height = getExpectHeight(view);

		return imageSize;
	}

	/**
	 * 根据view获得期望的高度
	 *
	 * @param view
	 * @return
	 */
	private static int getExpectHeight(View view) {

		int height = 0;
		if (view == null)
			return 0;

		final ViewGroup.LayoutParams params = view.getLayoutParams();
		// 如果是WRAP_CONTENT，此时图片还没加载，getWidth根本无效
		if (params != null
				&& params.height != ViewGroup.LayoutParams.WRAP_CONTENT) {
			height = view.getWidth(); // 获得实际的宽度
		}
		if (height <= 0 && params != null) {
			height = params.height; // 获得布局文件中的声明的宽度
		}

		if (height <= 0) {
			height = getImageViewFieldValue(view, "mMaxHeight");// 获得设置的最大的宽度
		}

		// 如果宽度还是没有获取到，憋大招，使用屏幕的宽度
		if (height <= 0) {
			DisplayMetrics displayMetrics = view.getContext().getResources()
					.getDisplayMetrics();
			height = displayMetrics.heightPixels;
		}

		return height;
	}

	/**
	 * 根据view获得期望的宽度
	 *
	 * @param view
	 * @return
	 */
	private static int getExpectWidth(View view) {
		int width = 0;
		if (view == null)
			return 0;

		final ViewGroup.LayoutParams params = view.getLayoutParams();
		// 如果是WRAP_CONTENT，此时图片还没加载，getWidth根本无效
		if (params != null
				&& params.width != ViewGroup.LayoutParams.WRAP_CONTENT) {
			width = view.getWidth(); // 获得实际的宽度
		}
		if (width <= 0 && params != null) {
			width = params.width; // 获得布局文件中的声明的宽度
		}

		if (width <= 0)

		{
			width = getImageViewFieldValue(view, "mMaxWidth");// 获得设置的最大的宽度
		}
		// 如果宽度还是没有获取到，憋大招，使用屏幕的宽度
		if (width <= 0)

		{
			DisplayMetrics displayMetrics = view.getContext().getResources()
					.getDisplayMetrics();
			width = displayMetrics.widthPixels;
		}

		return width;
	}

	/**
	 * 通过反射获取imageview的某个属性值
	 *
	 * @param object
	 * @param fieldName
	 * @return
	 */
	private static int getImageViewFieldValue(Object object, String fieldName) {
		int value = 0;
		try {
			Field field = ImageView.class.getDeclaredField(fieldName);
			field.setAccessible(true);
			int fieldValue = field.getInt(object);
			if (fieldValue > 0 && fieldValue < Integer.MAX_VALUE) {
				value = fieldValue;
			}
		} catch (Exception e) {
		}
		return value;

	}
}
